Programming Articles - Page 2995 of 3366

Synchronization between processesMultiprocessing is a package which supports spawning processes using an API. This package is used for both local and remote concurrencies. Using this module, programmer can use multiple processors on a given machine. It runs on Windows and UNIX os.All equivalent synchronization primitives are present in this package.Example codefrom multiprocessing import Process, Lock    def my_function(x, y):       x.acquire()       print ('hello world', y)       x.release()       if __name__ == '__main__':       lock = Lock()    for num in range(10): Process(target= my_function, args=(lock, num)).start()Here one instance can lock ... Read More

In Python provides SunPy package for create solar image. In this package has different files which are solar data of proton/electron fluxes from various solar observatory and solar labs. Using pip install sunpy command, we can install sunpy package. Here we plot a sample AIA image. AIA is Atmospheric Imaging Assembly. This is another instrument board of the SDO. Here we use sunpy.Map() function to create a map from one of the supported data products. Example code import sunpy.map import matplotlib.pyplot as plt import sunpy.data.sample my_aia = sunpy.map.Map(sunpy.data.sample.AIA_171_IMAGE) fig = plt.figure() ax = plt.subplot(111, projection=my_aia) my_aia.plot() my_aia.draw_limb() ... Read More

For solving this problem we need requests module.For installing requests module, we need this command to get executed at command line.pip install requestsScrapingImport requests module.Then we need to fetch data from URL.Using UTF-8 decode the text.Then convert string into a list of words.Ordered FindingTraverse the list of words using loop.Then compare the ASCII value of adjacent character of each word.If the comparison is true then print ordered word otherwise store the unordered word.Example codeimport requests    def Words_find():       my_url = ""#put thisurl of .txt files in any website       my_fetchData = requests.get(my_url)       ... Read More

In Python in some cases we use Single Underscore(_) and some cases we use Double Underscores (__). In Python has following cases, where we use underscore. If we want to store the value of last expression in interpreter. If we want to ignore some values. For declaration of variable or function. To separate digits of number lateral value. It is also used as ‘Internationalization (i18n)’ or ‘Localization (l10n)’ functions. Now some examples on every cases. Used in interpreter The Python Interpreter stores the last expression value in the '_'. >>> 20 20 >>> _ ... Read More

The JSON (Java Script Object Notation) is light weight, well accepted data interchange format. Using JSON formatting techniques in Python, we can convert JSON strings to Python objects, and also convert Python Objects to JSON strings.To use these functionalities, we need to use the json module of Python. The json module comes with the Python standard library. So at first we have to import it first.import jsonConverting Python objects to JSON StringIn the json module, there are some methods like dump(), and dumps() to convert Python objects to JSON strings. The dump() method takes two arguments, the first one is ... Read More

Using Python, we can easily convert data into different types. There are different functions for Type Conversion. We can convert string type objects to numeric values, perform conversion between different container types etc. In this section we will see how the conversions can be done using Python. Converting String to Numeric Types To convert from String type objects to Numeric Objects, there are different methods like int(), float() etc. Using the int() method we can convert any number as string to integer value (base 10). It takes the string type argument, default base is 10, We can also specify the ... Read More

In this section we will see how two sorted lists can be merged using the heapq module in Python. As an example, if list1 = [10, 20, 30, 40] and list2 = [100, 200, 300, 400, 500], then after merging it will return list3 = [10, 20, 30, 40, 100, 200, 300, 400, 500]To perform this task, we will use the heapq module. This module comes with Python as Standard Library Module. So we need to import it before using it.import heapqThe heapq module has some properties. These are like below −Method heapq.heapify(iterable)It is used to convert an iterable dataset ... Read More

Our task is to create a child process and display process id of both parent and child process using fork() function in Python.When we use fork(), it creates a copy of itself, it is a very important aspect of LINUX, UNIX. fork() is mainly applicable for multithreading environment that means the execution of the thread is duplicated created a child thread from a parent thread. When there is an error, the method will return a negative value and for the child process, it returns 0, Otherwise, it returns positive value that means we are in the parent process.The fork() module ... Read More

To determine if a String is a legal Java Identifier, use the Character.isJavaIdentifierPart() and Character.isJavaIdentifierStart() methods.Character.isJavaIdentifierPart()The java.lang.Character.isJavaIdentifierPart() determines if the character (Unicode code point) may be part of a Java identifier as other than the first character.A character may be part of a Java identifier if any of the following are true.it is a letterit is a currency symbol (such as '$')it is a connecting punctuation character (such as '_')it is a digitit is a numeric letter (such as a Roman numeral character)Character.isJavaIdentifierStart()The java.lang.Character.isJavaIdentifierStart() determines if the character (Unicode code point) is permissible as the first character in a Java ... Read More

To compare two Java char arrays, use the Arrays.equals() method.Let us first declare and initialize some char arrays.char[] arr1 = new char[] { 'p', 'q', 'r' }; char[] arr2 = new char[] { 'p', 'r', 's' }; char[] arr3 = new char[] { 'p', 'q', 'r' };Now let us compare any two of the above arrays.Arrays.equals(arr1, arr2));In the same way, work it for other arrays and compare them.The following is an example.Example Live Demoimport java.util.*; public class Demo {    public static void main(String []args) {       char[] arr1 = new char[] { 'p', 'q', 'r' };     ... Read More